The opening and closing switching contacts for switching currents in an electrical switching device result in switching arcs between the switching contacts. These switching arcs lead to increasing contact erosion on the switching contacts, and thus to wear of the switching contacts. Since this wear influences the switching behavior of the switching device, the contact erosion of the switching contacts must be monitored.
EP 1 022 904 A1 discloses the use of a camera for imaging monitoring of the wear of the switching contacts. Another apparatus which is disclosed in EP 1 022 904 A1 for monitoring the wear is numerical monitoring with the aid of a switching operation counter, or numerical monitoring on the basis of addition of the disconnection currents.
DE 101 09 952 A1 discloses an arrangement by which a fault arc in an electrical switchgear assembly can be identified by way of an optical waveguide. For this purpose, the light originating from a fault arc that occurs is injected radially into the optical waveguide, and is passed to a detector. The injected and detected light is then used in a disturbance light detection circuit to identify whether a fault arc has occurred.